Airi Amamiya, a 14-year-old schoolgirl, logs into the popular VR game Masters of Astrea Online, dreaming of exploring a fantastical world of magic and adventure. But an unknown glitch occurs: her consciousness becomes permanently linked to the game character.
Astrea is now her reality. There is no exit button, and the death of the character means the death of Airi. Soon, she discovers a mysterious class that didn't exist in the official game data...

Magical Girl.

To return home, Airi must survive in a world that is no longer a game.